This invention relates to a modulator for control grid modulation of a high voltage electron tube, and more particularly to a universal modulator for electronic countermeasures and radar applications with a wide range of pulse widths.
In electronic countermeasure applications in particular, designers have been striving to achieve a universal modulator with minimal delay plus rise for repeater operation, very short pulse capability for efficient peak power use, and very long pulse to CW capability to allow the source to counter a multitude of different threats.
Present modulators are able to meet the rise plus delay requirements for voltage swings in the order of 350 volts; however, minimum pulsewidths are limited to the 0.5 microsecond range with off plus delays running well beyond 100 nanoseconds. In addition, the maximum pulsewidth is limited to the 50-microsecond range.
For example, U.S. Pat. No. 4,193,032 by Milberger et al discloses apparatus for pulsing a high speed transmitter having pulser delay times in the nanosecond range. The combination of solid state and spark gap devices provides protection against high voltage arcs for both transient and power follow-through conditions.
U.S. Pat. No. 4,159,479, by Jaklitch et al, discloses a radar ECM simulator using PIN modulators, which is a common device for high-speed modulators. U.S. Pat. No. 4,140,980, by Cummings, discloses a compensation circuit for trailing edge distortion of pulsewidth modulated signals.